1. Technical Field
The present invention relates to a surface treatment method, and particularly to a surface treatment method which is preferably applied to manufacturing of a color filter substrate by an ink-jet process, and manufacturing of an electro-optical device by an ink-jet process.
2. Related Art
There has been known that an alignment film is formed on a surface of a substrate by an ink-jet process. In the ink-jet process, before an alignment film forming process, a process of adjusting wettability of a substrate surface as a base of an alignment film is performed. An atmospheric-pressure plasma method is one technique used in the process of adjusting wettability of the substrate surface. By the atmospheric-pressure plasma method, the substrate surface is exposed to excited radicals or plasma under atmospheric pressure to adjust surface energy or wettability of the substrate surface.
The example describes a plasma treatment apparatus which supply the substrate surface with excited radicals uniformly. According to the example, a treatment gas is introduced to an electric discharge region between a porous plate i.e. an electrode and a substrate surface through the porous plate as the electrode. Further according to the example, due to a function of the porous plate, the same electric discharge state is attained at the surface anywhere in the electric discharge region. As a result, the degree of the process the substrate surface undergoes becomes uniform across the entire surface.
JP-A-2003-272837 (FIG. 1 to FIG. 3) is an example of related art.
The porous plate of the example has many holes through which the treatment gas passes. Because of this, the porous plate tends to be decomposed by the treatment gas. Furthermore, when the porous plate is decomposed, thereby substances are generated and adhere to the substrate surface as impurities, causing a fear of deteriorating of a panel.
Moreover, the present inventor has found that when the electrode is caused to move relative to the surface continuously, unevenness in processing is possible to be generated, even if the porous plate is used.